Athletic shoes are expensive as they must be made of excellent materials by skilled craftsmen, must be made of superior materials and should be well fitted to withstand the extreme pressures and abuses which they encounter as athletes wearing them attempt superior feats of physical prowess. Also, the surfaces on which sporting contests are conducted vary from contest to contest, from one field to another, and from day to day. For example, as to one sport such as foot ball, we may have natural grass, various kinds of artificial grass or rugs, and various kinds of soil. In addition, the weather condition may be dry and sunny, raining, sleeting, or freezing resulting in a fast, dry surface, a soft surface, a muddy surface, a slick surface, a frozen surface and combinations thereof. To permit best athletic performances on such field conditions, the shoe outsoles must have a tread best suited to the particular field surface and the condition thereof at the time of use and also have an upper well fitted to the athlete's foot and ankle. The need for a replacement or removable outsole with a tread thereon best suited to meet the particular surface conditions of the playing field and on a particular day has long been acknowledged but to provide the same with a sturdy and reliable shoe fitted to the extremes which may be encountered in athletic endeavors has been wanting.
A sample of the endeavors which might be used to satisfy the long-felt need in this art, and the most pertinent prior art known to applicant are the following United States Letters Patent:
______________________________________ PATENTEE PATENT NUMBER ISSUE DATE ______________________________________ M. C. Clark 980,173 Dec. 27, 1910 M. Rasmussen 1,051,448 Jan. 28, 1913 F. Victor 1,318,247 Oct. 7, 1919 W. M. Jessup 1,341,323 May 25, 1920 A. Siekacz 1,773,242 Aug. 19, 1930 E. Richter 2,178,025 Oct. 31, 1939 E. C. Heilhecker 2,183,277 Dec. 12, 1939 J. Fein 2,200,080 May 7, 1940 S. H. Geffner 2,205,091 June 18, 1940 E. Danielius 2,552,943 May 15, 1951 W. Epsztejn 2,528,951 Nov. 7, 1950 M. Sabbagh 2,664,650 Jan. 5, 1954 W. C. C. Burton, Jr. 2,839,845 June 24, 1958 C. B. Reinhart 3,012,340 Dec. 12, 1961 R. T. Kauffman et al 3,019,534 Feb. 6, 1962 A. Herschdorf 3,083,476 April 2, 1963 Claude-Roger Isman 3,878,626 Apr. 22, 1975 ______________________________________
In general such prior art patents failed to disclose shoes with removable outsoles which would stand up under the rigors and pressures of highly competitive athletic endeavors and which would provide desirable engagement with all surface conditions of the playing field.